Inflator

Abstract

An inflator for a vehicle occupant restraint system. The inflator includes a cylindrical outer wall having a longitudinal axis and a first opening formed therealong for enabling fluid communication between an interior of the inflator and an exterior of the inflator. A first inflation fluid source is positioned within the outer wall. A baffle system is fluidly interposed between the first inflation fluid source and the outer wall for conveying inflation fluid between the first inflation fluid source and the outer wall, and for cooling the inflation fluid. A second opening enables fluid communication between the first inflation fluid source and the baffle system, and a third opening enables fluid communication between the baffle system and the outer wall. The first opening is substantially radially aligned with the second opening. An expanded metal mesh buffer may be positioned between within the baffle system. Openings enabling fluid communication between the baffle system and the exterior of the baffle system, any openings provided within the baffle system, and the opening enabling fluid communication between the interior and exterior of the inflator housing are cooperatively positioned to direct the flow of an inflation through the baffle system in directions substantially perpendicular to and/or substantially parallel to the longitudinal axis. Also disclosed is a vehicle occupant restraint system incorporating an inflator in accordance with the present invention.

1. An inflator for a vehicle occupant protection system, the inflator comprising:
 a cylindrical outer wall having a longitudinal axis and at least one opening formed therealong for enabling fluid communication between an interior of the inflator and an exterior of the inflator; 
 a first inflation fluid source positioned within the outer wall; 
 a baffle system fluidly interposed between the first inflation fluid source and the outer wall for conveying inflation fluid between the first inflation fluid source and the outer wall; 
 at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system; and 
 at least one opening for enabling fluid communication between the baffle system and the outer wall, 
 the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system being substantially radially aligned with the at least one opening for enabling fluid communication between an interior of the inflator and an exterior of the inflator, 
 the at least one opening for enabling fluid communication between the baffle system and the outer wall being angularly spaced approximately 90° apart from the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system; 
 wherein inflation fluid entering the baffle system from the first inflation fluid source is directed to the at least one opening for enabling fluid communication between the baffle system and the outer wall, 
 wherein the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system, the at least one opening for enabling fluid communication between the baffle system and the outer wall, and the at least one opening for enabling fluid communication between the interior of the inflator and the exterior of the inflator are arranged such that inflation fluid conveyed through the baffle system from the first inflation fluid source to the outer wall flows through the baffle system in directions substantially parallel to a plane perpendicular to the longitudinal axis, and through the baffle system alternately in directions substantially parallel to a plane perpendicular to the longitudinal axis and in directions substantially parallel to the longitudinal axis. 
 
   
   
     2. The inflator of  claim 1  further including another at least one opening for enabling fluid communication between the interior of the inflator and the exterior of the inflator, the other at least one opening being formed along the outer wall substantially diametrically opposite the least one opening formed along the outer wall for enabling fluid communication between the interior of the inflator and the exterior of the inflator. 
   
   
     3. An inflator for a vehicle occupant protection system the inflator comprising:
 a cylindrical outer wall having a longitudinal axis and at least one opening formed therealong for enabling fluid communication between an interior of the inflator and an exterior of the inflator; 
 a first inflation fluid source positioned within the outer wall; 
 a baffle system fluidly interposed between the first inflation fluid source and the outer wall for conveying inflation fluid between the first inflation fluid source and the outer wall; 
 at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system; and 
 at least one opening for enabling fluid communication between the baffle system and the outer wall, 
 the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system being substantially radially aligned with the at least one opening for enabling fluid communication between an interior of the inflator and an exterior of the inflator, 
 the at least one opening for enabling fluid communication between the baffle system and the outer wall being angularly spaced approximately 90° apart from the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system, 
 wherein inflation fluid entering the baffle system from the first inflation fluid source is directed to the at least one opening for enabling fluid communication between the baffle system and the outer wall, 
 wherein the baffle system comprises an outer baffle positioned radially inwardly of the outer wall and in fluid communication with the outer wall and 
 an inner baffle positioned radially inwardly of the outer baffle so as to enable fluid communication between the inflation fluid source and the inner baffle, 
 wherein the at least one opening for enabling fluid communication between the inflation fluid source and the baffle system is formed along the inner baffle, and wherein the inflator further includes; 
 another at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system, the other at least one opening being formed along the inner baffle substantially diametrically opposite the at least one opening formed along the inner baffle for enabling fluid communication between the first inflation fluid source and the baffle system; 
 another at least one opening for enabling fluid communication between the baffle system and the outer wall, the other at least one opening being formed along the outer baffle substantially diametrically opposite the at least one opening formed along the outer baffle for enabling fluid communication between the baffle system and the outer wall; and 
 another at least one opening for enabling fluid communication between the interior of the inflator and the exterior of the inflator, the other at least one opening being formed along the outer wall substantially diametrically opposite the at least one opening formed along the outer wall for enabling fluid communication between the interior of the inflator and the exterior of the inflator, 
 and wherein inflation fluid entering the baffle system from the first inflation fluid source is directed to at least one of the at least one opening for enabling fluid communication between the baffle system and the outer wall and the other at least one opening for enabling fluid communication between the baffle system and the outer wall. 
 
   
   
     4. The inflator of  claim 3  wherein the inner baffle and the outer baffle are substantially concentrically arranged about the longitudinal axis. 
   
   
     5. The inflator of  claim 3  wherein the at least one opening for enabling fluid communication between the baffle system and the outer wall is formed along the outer baffle. 
   
   
     6. The inflator of  claim 3  further comprising a buffer positioned between the inner baffle and the outer baffle for cooling inflation fluid flowing between the inner and outer baffles. 
   
   
     7. The inflator of  claim 6  wherein the buffer comprises an expanded metal mesh. 
   
   
     8. An inflator for a vehicle occupant protection system, the inflator comprising:
 a cylindrical outer wall having a longitudinal axis and at least one opening formed therealong for enabling fluid communication between an interior of the inflator and an exterior of the inflator; 
 a first inflation fluid source positioned within the outer wall; 
 a baffle system fluidly interposed between the first inflation fluid source and the outer wall for conveying inflation fluid between the first inflation fluid source and the outer wall; 
 at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system; and 
 at least one opening for enabling fluid communication between the baffle system and the outer wall, 
 the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system being substantially radially aligned with the at least one opening for enabling fluid communication between an interior of the inflator and an exterior of the inflator, 
 the at least one opening for enabling fluid communication between the baffle system and the outer wall being angularly spaced approximately 90° apart from the at least one opening for enabling fluid communication between the first inflation fluid source and the baffle system, 
 wherein inflation fluid entering the baffle system from the first inflation fluid source is directed to the at least one opening for enabling fluid communication between the baffle system and the outer wall, the inflator 
 further including a second inflation fluid source positioned within the outer wall in fluid isolation from the first inflation fluid source, and wherein the baffle system is fluidly interposed between the second inflation fluid source and the outer wall for conveying inflation fluid between the second inflation fluid source and the outer wall. 
 
   
   
     9. The inflator of  claim 8  wherein the second inflation fluid source comprises a quantity of a gas generant composition. 
   
   
     10. The inflator of  claim 9  wherein the gas generant composition comprises a smokeless gas generant composition. 
   
   
     11. The inflator of  claim 9  wherein the second inflation fluid source is fluidly isolated from the first inflation fluid source by a barrier configured for preventing sympathetic ignition of the second gas generant composition in response to ignition of the first gas generant composition, and for enabling release of inflation gas into the baffle system upon ignition of the second gas generant composition.